Arthritis refers to inflammation of a joint. The inflammation can affect any of the important structures inside a joint, including the joint lining (synovium), bones, cartilage, or supporting tissues. Common symptoms of arthritis include pain, stiffness, and swelling of the joint. The condition may affect one or several joints throughout the body.
There are many possible causes of arthritis, although some are much more common than others. Some types of arthritis respond well to treatment and resolve without any lingering effects, whereas other types of arthritis are more difficult to control and can be disabling.
This topic provides an overview of arthritis; more detailed information about the various types of arthritis is also available. (See 'Where to get more information' below.)
There are many possible causes of arthritis, including age-related wear and tear, infections, autoimmune conditions, injuries, and others. Topic reviews that discuss specific types of arthritis are available separately. (See 'Where to get more information' below.)
Joint symptoms — The most common symptoms of arthritis include joint pain and stiffness. There may also be joint tenderness, swelling, and limited movement of one or more joints. The skin over the joint is sometimes red and warm.
There are two main types of arthritis: inflammatory and noninflammatory. Examples of inflammatory arthritis include infectious arthritis, rheumatoid arthritis, and gout. An example of noninflammatory arthritis is osteoarthritis, the most common type of arthritis. The location, timing, and pattern of joint pain, as well as the presence of swelling and symptoms outside the joint (such as rash), can help to distinguish between inflammatory and noninflammatory arthritis.
Inflammatory arthritis — Inflammatory arthritis usually causes joint stiffness with rest, especially morning stiffness. Certain types of inflammatory arthritis, such as rheumatoid arthritis and the arthritis of systemic lupus erythematosus (SLE), affect joints symmetrically (ie, affect the same joints on both sides of the body).
Noninflammatory arthritis — Noninflammatory arthritis usually causes pain that is aggravated by movement and weightbearing and is relieved by rest. Joints on one or both sides of the body may be affected.
The process of diagnosing arthritis involves several steps. A medical history and physical examination usually provide the most helpful information; laboratory tests, imaging tests (such as x-rays), and other tests are sometimes needed.
Laboratory and imaging tests — Laboratory and imaging tests are sometimes, but not always, needed to determine the cause of arthritis.
Blood tests may be recommended. For example, if rheumatoid arthritis or systemic lupus erythematosus (SLE) is suspected, it can be helpful to test the blood for antibodies that are commonly present in these diseases. Examples include the rheumatoid factor (RF) for rheumatoid arthritis and the antinuclear antibody (ANA) for SLE.
Testing of the fluid inside a joint, called the synovial fluid, is often helpful in determining the cause of a person’s arthritis. After making the skin numb, the fluid is removed by inserting a needle inside the joint and withdrawing a sample of fluid. This procedure is sometimes called a “joint tap.” Analysis of the joint fluid is particularly helpful in confirming that the arthritis is inflammatory and in establishing a diagnosis of septic arthritis (due to bacterial infection), gout, or pseudogout.
X-rays provide detailed pictures of bones. Other imaging tests, such as ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT scan), provide images of the tissues inside and surrounding the joints. One or more of these imaging tests may be recommended to detect erosions (bone damage due to arthritis), fractures, calcium deposits, or changes in the shape of a joint.
For many types of arthritis, changes in the joint are not visible on x-ray for months or even years. However, x-rays are often useful to monitor over time.
WHEN TO SEEK HELP
Some signs and symptoms of arthritis require urgent medical care. If you have one or more swollen joints and any of the following, you should seek medical care as soon as possible.
●An inability to function due to joint pain
●An overall sense of feeling ill
●Sudden weakness of specific muscle groups
The treatment of arthritis depends upon the specific cause (see "Patient information: Osteoarthritis treatment (Beyond the Basics)" and "Patient information: Rheumatoid arthritis treatment (Beyond the Basics)"). Common treatments include physical and occupational therapy, pain relievers (such as acetaminophen), antiinflammatory medications (such as ibuprofen), and medications that suppress the immune system (such as prednisone or methotrexate).
WHERE TO GET MORE INFORMATION
Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient information: Bursitis (The Basics)
Patient information: Ganglion cyst (The Basics)
Patient information: Osteoarthritis (The Basics)
Patient information: Arthritis and exercise (The Basics)
Patient information: Knee replacement (The Basics)
Patient information: Hip replacement (The Basics)
Patient information: Knee pain (The Basics)
Patient information: Hand pain (The Basics)
Patient information: Hip pain in older people (The Basics)
Patient information: Rheumatoid arthritis (The Basics)
Patient information: Rheumatoid arthritis and pregnancy (Beyond the Basics)
Patient information: Juvenile rheumatoid arthritis (The Basics)
Patient information: Gout (The Basics)
Patient information: Calcium pyrophosphate deposition disease (pseudogout) (The Basics)
Patient information: Psoriatic arthritis in adults (The Basics)
Patient information: Psoriatic arthritis in children (The Basics)
Patient information: Reactive arthritis (Reiter syndrome) (The Basics)
Patient information: Septic arthritis (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient information: Osteoarthritis symptoms and diagnosis (Beyond the Basics)
Patient information: Rheumatoid arthritis symptoms and diagnosis (Beyond the Basics)
Patient information: Gout (Beyond the Basics)
Patient information: Pseudogout (Beyond the Basics)
Patient information: Systemic lupus erythematosus (SLE) (Beyond the Basics)
Patient information: Ankylosing spondylitis and other spondyloarthritis (Beyond the Basics)
Patient information: Psoriatic arthritis (Beyond the Basics)
Patient information: Reactive arthritis (formerly Reiter syndrome) (Beyond the Basics)
Patient information: Osteoarthritis treatment (Beyond the Basics)
Patient information: Rheumatoid arthritis treatment (Beyond the Basics)
Patient information: Joint infection (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Arthritis associated with gastrointestinal disease
Clinical features of rheumatoid arthritis
Clinical manifestations and diagnosis of psoriatic arthritis
Diagnosis and differential diagnosis of rheumatoid arthritis
Imaging techniques for evaluation of the painful joint
Evaluation of the adult with monoarticular pain
Evaluation of the adult with polyarticular pain
General principles of management of rheumatoid arthritis in adults
Overview of the systemic and nonarticular manifestations of rheumatoid arthritis
Septic arthritis in adults
Specific viruses that cause arthritis
Treatment of psoriatic arthritis
Non-radiographic axial spondyloarthritis, undifferentiated spondyloarthritis, and peripheral spondyloarthritis
The following organizations also provide reliable health information.
●National Library of Medicine
(www.nlm.nih.gov/medlineplus/arthritis.html, available in Spanish)
●National Institute of Arthritis and Musculoskeletal and Skin Diseases
●National Institute on Aging
(www.nia.nih.gov/health/publication/arthritis-advice, available in Spanish)
●American College of Rheumatology
●The Arthritis Foundation
Patient Support — There are a number of online forums where patients can find information and support from other people with similar conditions.
●About.com Arthritis Forum